It may have been a premeditated outburst or a sudden slip-of-the-lip, but either way Sun Microsystems chief executive Jonathan Schwartz is claiming that Apple next week will announce a plan to replace the default Mac OS X file system with the Sun-developed ZFS.

Schwartz made the plans public while speaking to analysts and members of the media at a company event in nation's capital on Wednesday. The event was primarily aimed at hyping a more flexible array of blade servers.

"In fact, this week you'll see that Apple is announcing at their Worldwide Developer Conference that ZFS has become the file system in Mac OS 10," he said while speaking of his firm's file system (Real Player video link).

Originally conceived by Sun as a foundation for its Solaris operating system, ZFS features high capacity, a novel on-disk structure, lightweight instances, and the integration of the concepts for volume management.

Unlike a traditional file system, which resides on a single device and thus requires a volume manager to use more than one device, ZFS is built on top of virtual storage pools called zpools. A pool is constructed from virtual devices, each of which is either a raw device, a mirror of one or more devices, or a RAID-Z group of two or more devices.

ZFS would replace Apple's current default file system, Journaled HFS+, beginning with October's release of Leopard, according to Schwartz' comments.

I've heared ZFS is great, so it looks great. They'll probably include ZFS support in 10.4.10 once they've actually announced this themselves, and hopefully it'll be backwards compatible in some ways... we hope.

If it isn't going to be compatible, then it'll suck. Otherwise, all is well, no?

This makes sense. That must be why there hasn't been much news about ZFS development lately. It was pulled under Apple's iron curtain where the boot problem and other bugs are hopefully being fixed. Maybe Apple decided to let Sun have the thunder on this one by announcing it before them (since it is their tech and all and Apple should have plenty to announce for themselves).

Rethinking this... he didn't specifically come out and say ZFS will become the **default** filesystem for OS X 10.5 he said "ZFS will be the filesystem..." and could have very well meant to say "ZFS will be a filesystem for OS X 10.5 ..."

Also as far as time machine using ZFS I wouldn't be too sure... It'll be a safe bet that initially TM will work with HFS+ as well as ZFS and thus might not be taking advantage of specific features of ZFS - at least not right away...

I would think that ZFS would allow you to have a virtual filesystem that crosses physical boundaries of hard drives.

I ran out of space on my main/boot harddrive because of video. With ZFS, I think I should be able to extend the filesystem so that it looks like all my videos are under my own username/home directory but actually are on 2 separate drives.

Time Machine will definitely work with HFS+, but it requires a second volume to be activated. Besides, it makes a copy of the modified files/sectors, which is slow. ZFS snapshots are not bringing any overhead, it's because of the way the file system works. It can be faster (in some situations - much faster) than HFS even when using a single volume. The trick is clever scheduling of the read/write operations. If you are watching movie, for example, the reading operation will have high priority and there will be no dropouts. For the Mac OS X Server with RAID the performance improvement may be dramatic. It is VERY fast for DB etc. It also has a built-in compression (I guess encryption can be added too), which, unlike some old Windows and mac implementations, further improve the performance on modern CPUs.
ZFS is VERY reliable. Unlike Journaling on HFS+, there is no performance penalty for increased (actually, much better than in HFS+) reliability.
If you make a search, you may find stunning performance results. This is not the best one:http://www.helios.de/news/news07/zfs.phtml
In many cases you may think this is impossible because it is beyond the hardware limits of the drive speed/interface bandwidth.
Microsoft failed to deliver the promised new file system with Vista. And Apple is going to speak very loudly about ZFS benefits.

I would think that ZFS would allow you to have a virtual filesystem that crosses physical boundaries of hard drives.

I ran out of space on my main/boot harddrive because of video. With ZFS, I think I should be able to extend the filesystem so that it looks like all my videos are under my own username/home directory but actually are on 2 separate drives.

Any insights on how ZFS might benefit users?

You are absolutely correct with your assumption. If you want to read more wikipedia is a good place to start.

I ran out of space on my main/boot harddrive because of video. With ZFS, I think I should be able to extend the filesystem so that it looks like all my videos are under my own username/home directory but actually are on 2 separate drives.

Exactly, you will be able. This particular feature is not really new for the UNIX world (it was there for ages) but it was never there in Mac OS 9 - X and all flavors of Windows. You should be careful with this however. If you are not using RAID configurations, you should avoid using, for example, 2 filesystems spread around two physical drives each (e.g. for increased performance) if at least one of them could reside on a single drive. You will be in trouble if one of the drives fails, or if you decide to remove it.

I think there's no question that ZFS will be a huge win for servers, and I wouldn't be surprised if it ended up being the default in MacOS X Server, or at least a strongly recommended option. I will be surprised, however, if it shows up as the default in MacOS X client. Pleasantly surprised, but still surprised.

I think there's no question that ZFS will be a huge win for servers, and I wouldn't be surprised if it ended up being the default in MacOS X Server, or at least a strongly recommended option. I will be surprised, however, if it shows up as the default in MacOS X client. Pleasantly surprised, but still surprised.

I will be surprised too, but this will make Time Machine actually usable

I don't see the point of having ZFS as the file system on an iPod. What advantages do you see?

Consistency. Currently the iPod uses HFS+, as does the Mac. On the PC side the iPod uses FAT32 and MS-Windows uses the same. Following on from there I just figured it would make sense to take the iPod in the same direction when upgrade to 10.5.

Not to derail the thread, but I use an external drive with my laptop for video and an aperture vault etc. I usually don't work at my desk which means a lot of plugging and unplugging my drive. Since zfs puts all the drives under one directory how would it respond to a harddrive (twice the size of the latop's for that matter) drifting in and out?

Or will I just have to create a virtual disk which is tied to the external to keep things nice?

Not to derail the thread, but I use an external drive with my laptop for video and an aperture vault etc. I usually don't work at my desk which means a lot of plugging and unplugging my drive. Since zfs puts all the drives under one directory how would it respond to a harddrive (twice the size of the latop's for that matter) drifting in and out?

Or will I just have to create a virtual disk which is tied to the external to keep things nice?

It doesn't do that automatically. It has the *capability* to do it, but it doesn't just take any disk you pop in and add it to a pool.

Wow,
I this is a really exciting development, I am a bit of a file system junkie and am glad to see apple jumping headfirst into ZFS. It seems a lot of the shortcomings of ZFS (i.e. bootable) have been under development for awhile now and are releasing late this year (coincidence?). Snapshots, data integrity, clean backups, seamless disk volume management, mirroring, striping, I/O priotities, oh my! These technologies have all been developed, tested and used in bits and pieces in the enterprise world for years now. The original Time Machine demo sounded great, but in the Beta releases to date it had been junk, it seemed to be an ugly implementation of a great concept, not very Apple.... It sounds like Apple is doing what they do best, taking complex technology and integrating it seamlessly to simplify the way we deal with computers. PCs have been stagnant using essentially the same storage and filesystem paradigm for decades now. I can't wait to see what wonderful things Apple can do with a modern filesystem like ZFS.

It does need a file system. Flash is usually formatted as FAT32 and the bigger 4GB+ cards are often NTFS. It just appears to most OSs as a disk.

Quote:

Originally Posted by audiopollution

I don't see the point of having ZFS as the file system on an iPod. What advantages do you see?

There's one advantage I'd see. Say you've a big networked drive sat on a network using a ZFS pool. How cool would it be to add that pool in to your networked iPod, iPhone or AppleTV and seamlessly have a huge media library to use. Or even viceversa so you no longer have to sync data between two drives.

Not to derail the thread, but I use an external drive with my laptop for video and an aperture vault etc. I usually don't work at my desk which means a lot of plugging and unplugging my drive. Since zfs puts all the drives under one directory how would it respond to a harddrive (twice the size of the latop's for that matter) drifting in and out?

Or will I just have to create a virtual disk which is tied to the external to keep things nice?

Imagine a user interface that will ask you what to do with an external drive when you connect it to the Mac for the first time. Similar to: 1- "Add the drive?" (the external drive's storage space will be added to the internal Macintosh HD drive); 2- "Keep as external", 3- "Use as mirror"... ); 4- .(..). This is the real reason why Leopard has been delayed till October.

Even if all things were equal; ZFS should provide a performance boost. I like HFS+ but it's carrying a *lot* of legacy code (6800 code emulated into powerPC emulated to x86). I'm only loosely familiar with ZFS but I'm mostly impressed (certainly hard to use up a 128 bit file system and it's capacity to "nest" file systems means it can be both efficient and virtually inexhaustable; in that small files can stay small -- generally, increasing the number of bits for a file system also increases the size of the smallest sector).

I'm more concerned about the user experience; I miss resource forks and metadata. I'm intrigued by ZFSs implimentation of Metadata but haven't explored it enough to know if it's useful. I still think file extensions are a *Bad* idea (the information should be metadata and generated as extensions on the fly only when dealing with more primitive (extension dependent) file systems for backward compatibility) and Aliases are far more useful than symbolic links. I have rather strong and specific ideas on what a filesystem should and shouldn't do (back in the days of SemperFi -- God that's over a decade ago -- I had extensive discussions with Apple engineers about this before HFS got it's "+"); There is nothing intrinsic to ZFS I object to but I would love to see a more user centric implimentation of a "Finder" than we currently have.